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7-30 Waters
|type= Rifle and single shot handgun |service= |used_by= |wars= |designer= Ken Waters |design_date= 1976 |manufacturer= |production_date= 1984 |number= |variants= |is_SI_specs= |parent= .30-30 Winchester |case_type= Rimmed |bullet= .284" (7 mm) |neck= .306 |shoulder= |base= .422 |rim_dia= .506 |rim_thick=.058 |case_length=2.04 |length=2.52 |case_capacity= |rifling= |primer= Large Rifle |max_pressure= |max_cup= 40,000 |filling= |filling_weight= |detonation= |yield= |is_SI_ballistics= |bw1=120 |btype1= Nosler Partition FP |vel1= 2700 |en1= 1940 |bw2=139 |btype2= Flat point |vel2= 2540 |en2= 1990 |bw3= 154 |btype3= Round nose |vel3= 2347 |en3= 1835 |bw4= |btype4= |vel4= |en4= |bw5= |btype5= |vel5= |en5= |test_barrel_length= 24" |balsrc= Cartridges of the World, 10th Ed., Barnes }} The 7-30 Waters cartridge was originally a wildcat cartridge developed by author Ken Waters in 1976 to give better performance to lever action rifle shooters than the parent .30-30 Winchester cartridge, by providing a higher velocity and flatter trajectory with a smaller, lighter bullet. By 1984, Winchester introduced a Model 94 rifle chambered for the 7-30 Waters, establishing it as a commercial cartridge. In 1986, Thompson/Center began chambering 10", 14" and 20" Contender barrels for the cartridge. Development Why neck down a .30 cal. cartridge to 7mm? This quote from a review of the 7-08 Rem. (a .308 Win. case necked down to 7mm), provides the answer. There are two primary reasons a 7mm recoils less than an comparably effective .30 cal. cartridge: (1) to match the 7mm's ballistic coefficient requires a significantly heavier .30 cal bullet; and (2) to drive that heavier .30 cal bullet at similar velocities (for kinetic energy and wind resistance ("time-to-target")), requires more powder. This combination of heavier bullets with heavier powder charges significantly increases the recoil of the .30 caliber. The .30-30 Winchester is typically limited to short ranges, primarily because of the relatively small case capacity and the 150 grain and 170 grain bullet weights. To compensate for this, Waters necked the cartridge down to use a 7mm bullet (.284 inches), rather than the original .308 caliber (7.62 mm) bullet. Because it was designed to function in lever action rifles, the 7-30 maintained the same low working pressure, yet Waters' original design fired a lighter bullet (139 grains) at a higher velocity (2600 f/s)."7-30 Waters", retrieved 2013 May 04 A typical .30-30 factory load fires a 150 grain bullet at 2390 f/s, while the current 7-30 factory load fires a 120 grain bullet at 2700 f/s. Muzzle energy is just over 1900 ft-lbs for both of these loads, but the lighter weight 7mm bullet has a higher velocity and flatter trajectory. Ammunition Lever action rifles with tubular magazines can only safely use spitzer bullets as the first cartridge in the chamber with only flat-pointed bullets in the magazine, or if the rifle is used as a 2-shot (1 cartridge in the chamber and only 1 in the magazine). Handloaders for single-shot 7-30 Waters rifles or pistols are not limited to flat nosed bullets and thus have a wide range manufacturers and weights of 7mm pointed bullets from which to choose. Manufactured Ammo Federal Cartridge offers manufactured 7-30 Waters cartridges -- the Federal Premium Vital-Shok firing a 120 grain (7.78 g) Sierra GameKing boat-tail soft point flat-nose bullet at 2700 fps with 1940 ft-lbs of energy.[http://www.federalpremium.com/products/rifle.aspx Federal Premium Ammunition, retrieved 2012 May 15] It has a sectional density of 0.213 Hornady Manufacturing Company does not offer 7-30 Waters LEVERevolution ammunition which would allow the safe use of pointed, ballistically efficient spitzer bullets in tubular magazines.[http://www.hornady.com/store/leverevolution Hornady LEVERevolution, retrieved 2012 May 15] Handloading Speer Bullets offers a 130 gr (8.42 gr), copper jacketed soft point flat-nosed bullet for use in lever action rifles. It has a sectional density of 0.23 and a ballistic coefficient of 0.257[http://www.speer-bullets.com/ballistics/detail.aspx?id=47 Speer Bullets, #1625 Hot-Cor, retrieved 2012 May 15] Hornady Manufacturing Company does not offer either FTX or MonoFlex bullets in 7mm/.284" caliber.[http://www.hornady.com/store/FTX Hornady FTX, retrieved 2012 May 15][http://www.hornady.com/store/MonoFlex-Bullets Hornady MonoFlex, retrieved 2012 May 15] These would allow the safe use of pointed, ballistically efficient spitzer bullets in tubular magazines. Firearms Rifles }} By 1982, Waters had perfected his new cartridge, firing a 139 grain flat point bullet at a muzzle velocity of 2600 f/s from a lever action rifle with a 24" barrel. By 1983, he had managed to attract the attention of Winchester, which led to the introduction of the Model 94 angle eject 20" barreled carbine and Model 94XTR angle eject 24" barreled rifle in the new caliber in 1984. After 13 years, production ceased in 1997. Thompson Center Arms' single-shot Contender and Encore rifles are both offered in 7-30 Waters in either stainless steel or blued steel through their custom shop.[http://www.tcarms.com/customShop/ Custom Shop, retrieved 2012 May 12] Handguns Thompson Center Arms began to chamber the 7-30 Waters in their Contender single shot pistol starting in 1986. Factory loads are capable of velocities of 2400 f/s from the 14" pistol barrel, making the 7-30 Waters one of the fastest commercial rounds available for the pistol. In addition, the single shot Contender and Encore pistols can safely use pointed bullets, which allows the handloader to gain additional retained velocity at long ranges for uses such as handgun hunting and metallic silhouette shooting. Usage Paco Kelly, of leverguns.com: }} Bullets in the 110 to 120 grain range are suitable for small game and varmints (handloads with 110s can nearly achieve 3000 ft/s); 120 to 154 grain range for deer; and 154 to 168 gr range are adequate for larger game at closer ranges.[http://www.chuckhawks.com/sd.htm The Sectional Density of Rifle Bullets, retrieved 2012 May 18] "The 7-30 Waters has proven its capabilities in the field on big game weighing up to 300 pounds at woods ranges. As this is written, two bullets of flat nose form are available to handloaders for use in rifles with tubular magazines. For whitetails, the 120 grain Nosler is an excellent performer, but when greater penetration is needed for Mule Deer and Black Bear, the 139 grain Hornady is a better choice." Nosler and Hornady no longer offer flat nose bullets in 7mm.[http://www.nosler.com/Bullets.aspx Nosler, Bullets, retrieved 2012 May 18][http://www.hornady.com/store/.284-7mm/ Hornady, .284 7mm Products, retrieved 2012 May 18] Best performance is had with the rifle barrel; with the shorter carbine barrels the .30-30 is a better choice. With the long barrel, however, the 7-30 provides flatter trajectory, and a longer effective range, as well as reduced recoil from the lighter bullets. Despite the advantages, the 7-30 still lags far behind the venerable .30-30 in popularity, however. Where the 7-30 has gained a strong foothold is in handguns. In the field of handgun metallic silhouette shooting, a suitably loaded 7-30 Waters provides performance equal to other 7mm wildcats, such as the 7mm International Rimmed, but without the work of forming cases. It also adds the bonus of being able to shoot commercial ammunition, with some performance loss. References * Ken Water's Pet Loads Eighth Edition''; Book by Wolfe Publishing Co., Inc., 2001, p. 221-226 Category:Pistol and rifle cartridges